ES2973426T3 - Separator for alkaline cells - Google Patents

Abstract

An alkaline electrochemical cell includes a cathode; a gelled anode having an anode active material and an electrolyte; and a separator disposed between the cathode and the anode; wherein the separator includes a non-conductive porous material having an average pore size of about 1 micrometer to about 5 micrometers, a maximum pore size of about 19 micrometers, and an air permeability of about 0.5 cc/cm2/s to about 3.8 cc/cm2/s at 125 Pa. (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Separator for alkaline cells

Cross reference to related applications

This application claims the benefit of United States Provisional Patent Application No. 62/559,385, filed on September 15, 2017.

Field

Current technology is generally related to the field of electrochemical cells. In particular, the technology is related to separators for electrochemical cells, the separators feature improved pore size and air permeability. WO 02/068746 discloses a laminated battery separator material. Document US 2014/0134498 refers to separator means for electrochemical cells. Document EP 2077593 discloses an alkaline battery separator, a process for its production and alkaline batteries. WO 03/043103 relates to a nonwoven separator for an electrochemical cell. EP 1737004 discloses a separator for an electrochemical element.

Summary

The present invention provides an alkaline electrochemical cell according to claim 1 and an alkaline electrochemical cell separator according to claim 7.

Various optional features are set forth in the dependent claims.

Brief description of the drawings

Figure 1 illustrates an interaction graph for non-delay ANSI performance for an LR6 cell that includes a separator in accordance with the present disclosure.

Figure 2 is a graph illustrating personal care performance for an LR6 cell that includes a separator in accordance with the present disclosure.

Figure 3 is a graph illustrating the high temperature performance of the toy test after 1 week of storage at 160°F, and of the play test after 2 weeks of storage at 130°F, for an LR6 cell. which includes a spacer in accordance with the present disclosure.

Figure 4 is a graph illustrating the high temperature DSC testing performance of the LR6 cell after 2 weeks of storage at 130°F.

Figure 5 illustrates an interaction graph for a comparison of the non-delay ANSI performance of LR6 cells that include a separator in accordance with the present disclosure.

Figure 6 is a graph illustrating the DSC performance of LR6 cells including a separator in accordance with the present disclosure.

Figure 7 is a graph illustrating personal care performance for LR6 cells and whose performance is illustrated in Figure 5 and Figure 6.

Figure 8 is a graph illustrating high temperature storage performance for LR6 cells and whose performance is illustrated in Figure 5 and Figure 6.

It should also be noted that the design or configuration of components presented in these figures are not to scale and/or are intended for illustrative purposes only.

Detailed description

Various embodiments are described below. It should be noted that the specific embodiments are not intended to be an exhaustive description or limitation of the broader aspects discussed herein. An aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and may be practiced with any other embodiment.

As used herein, "approximately" will be understood by those of ordinary skill in the art and will vary to some extent depending on the context in which it is used. If there are uses of the term that are not clear to those skilled in the art, given the context in which it is used, "about" will mean up to plus or minus 10% of the particular term.

As used herein, the term "zinc anode" refers to an anode that includes zinc as an active anode material.

As used herein, "fines" are particles that pass through a standard 200 mesh sieve in a normal sieving operation (i.e., with the sieve shaken by hand). "Dust" consists of particles that pass through a standard 325 mesh sieve in a normal sieving operation. "Coarse" consists of particles that do not pass through a standard 100 mesh sieve in a normal sieving operation. The mesh sizes and corresponding particle sizes as described here apply to a standard test method for sieve analysis of metal powders that is described in ASTM B214. Typically, fines comprise particles less than 75 pm, coarse particles comprise particles greater than 150 pm, and powder comprises particles less than 45 pm.

As used herein, the term "ppm" means parts per million by weight, unless explicitly stated otherwise.

As used herein, the term "air permeability" denotes the volume of air that is allowed to flow per area of the separator.

The present disclosure is directed to improving the performance of cells, such as alkaline cells. The disclosure is also directed at suppressing undesirable reactions at the separator-electrode interface that can cause an electrical short circuit from the anode to the cathode.

Alkaline electrochemical cells are equipped with a separator to physically separate the anode and cathode and prevent electronic current from passing through them. Additionally, the separator functions to allow the passage of ionic current with minimal obstacles and keep the zinc surface adequately wetted by the electrolyte. Ideally, the separator should have a uniform dry thickness and a uniform pore size distribution.

Conventional alkaline cells typically employ a nonwoven separator sheet as a separator. The sheet is normally rolled or wrapped around itself to form a cylindrical shape which is then arranged between the anode and cathode electrode materials, the anode material being contained within the separator. Many times, the winding or wrapping is done multiple times to ensure sufficient and efficient separation between the electrodes (i.e. that there is enough overlap to ensure that leakage and short circuits between the anode and cathode are avoided). By way of illustration, when the wrapper is made with three integral wrappers, it can be said to have a 1x3 separator wrapper arrangement, i.e. a single sheet rolled/wrapped onto itself in a roll shape, three times. This arrangement typically results in a thick separator that occupies a significant volume in the cell, resulting in a substantial decrease in the available volume needed for active ingredients, such as zinc anode particles. This is especially true for smaller cells like the LR06 or LR03, where the outside dimensions of the cell are standardized and cannot be changed. It has now been discovered that the number of separator shells in electrochemical cells can be reduced by providing a separator with improved properties such as pore size and air permeability.

In one aspect, an alkaline electrochemical cell is provided. The cell includes a cathode, an anode including an anode active material and an electrolyte, and a separator disposed between the cathode and the anode. In another aspect, an alkaline electrochemical cell separator includes a porous material of desired pore size and air permeability to allow a reduced number of separator envelopes within the electrochemical cell, compared to conventional cell constructions.

The separator may be made of any porous woven or nonwoven, alkali-resistant, ion-permeable, non-conductive, synthetic or natural material, including, but not limited to, polymeric materials, Tencel® (lyocell), mercerized wood pulp, polypropylene, polyethylene, cellophane, cellulose, methylcellulose, rayon, nylon and combinations of these. In some embodiments, the non-conductive porous material includes an ion-permeable nonwoven sheet (barrier). In some embodiments, the separator is composed of a porous material including a paper composed of one or more polymeric fibers. The separator may be made of a porous material that includes one or more polymeric fibers with an effective amount of a surfactant embedded therein. Suitable polymeric materials for polymeric fibers include, but are not limited to, polyvinyl alcohol, polyamides, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyvinylidene fluoride, polyacrylonitrile, polypropylene, polyethylene, polyurethane and combinations, mixtures and copolymers thereof. Illustrative polymeric fibers may include, but are not limited to, materials such as rayon, nylon and the like, and combinations of two or more thereof. In some embodiments, the separator includes a nonwoven material formed from alkali resistant fibers. In some embodiments, the separator includes a nonwoven paper. In some embodiments, the non-conductive porous material includes polyvinyl alcohol and rayon fibers.

The separator has an air permeability in the range of approximately 0.5 cm3/[cm2.s] (cc/cm2/s) to approximately 3-8 cm3/[cm2.s] (cc/cm2/s), at 125 Pa. In In some embodiments, the separator has air permeability in the range of about 0.5 cm3/[cm2.s] (cc/cm2/s) to about 3 cm3/[cm2.s] (cc/cm2/s), at 125 Pa .

In various embodiments, the separator may have an air permeability in the range of about 0.83 cm3/[cm2.s] (50 cc/cm2/min (cubic centimeter per square centimeter per minute)) to about 30,000 cm3/[cm2.s] (30,000 cc/cm2/s) when measured at a pressure of 1 kilopascal (KPa). This includes an air permeability of approximately 1.67 cm3/[cm2.s] (100 cc/cm2/min) to approximately 167 cm3/[cm2.s] (10,000 cc/cm2/min), approximately 3.33 cm3/[cm2.s]. s] (200 cc/cm2/min) at approximately 133 cm3/[cm2.s] (8000 cc/cm2/min), approximately 5 cm3/[cm2.s] (300 cc/cm2/min) at approximately 83.3 cm3 /[ cm2.s] (5000 cc/cm2/min), approximately 8.33 cm3/[cm2.s] (500 cc/cm2/min) to approximately 50 cm3/[cm2.s] (3000 cc/cm2/min) , approximately 10 cm3/[cm2.s] (600 cc/cm2/min) to approximately 41.7 cm3/[cm2.s] (2500 cc/cm2/min), approximately 11.7 cm3/[cm2.s] (700 cc/ cm2/min) at approximately 33.3 cm3/[cm2.s] (2000 cc/cm2/min), or approximately 1.33 cm3/[cm2.s] (800 cc/cm2/min) at approximately 16.7 cm3/[cm2.s ] (1000 cc/cm2/min), at 1 KPa, and ranges between two of these values or less than any of these values. In some embodiments, the separator has an air permeability of about 8.33 cm3/[cm2.s] (500 cc/cm2/min) to about 50 cm3/[cm2.s] (3000 cc/cm2/min), at 1 KPa. In some embodiments, the separator has an air permeability of about 4 cm3/[cm2.s] (240 cc/cm2/min) to about 30.4 cm3/[cm2.s] (1824 cc/cm2/min), at 1 KPa.

In various embodiments, the separator may have a desired basis weight ranging from about 1 g/m2 to about 100 g/m2. This includes a desired grammage of about 1 g/m2 to about 90 g/m2, about 1 g/m2 to about 80 g/m2, about 5 g/m2 to about 70 g/m2, about 10 g/m2 to about 50 g/m2, about 20 g/m2 to about 32 g/m2, about 22 g/m2 to about 30 g/m2, or about 23 g/m2 to about 28 g/m2, and ranges between two of these values or less of any of these values. In some embodiments, the separator has a desired basis weight of about 20 g/m2 to about 32 g/m2. In other embodiments, the separator has a desired basis weight of about 24 g/m2 to about 30 g/m2.

An electrochemical cell provides superior high-speed performance when there is rapid and preferential transport of the electrolyte through the separator. Consequently, the separator is designed to be as thin as possible, in order to maximize discharge speed. In various embodiments, the separator may have a dry thickness ranging from about 10 pm to about 200 pm. This includes a dry thickness of about 20 pm to about 150 pm, about 40 pm to about 175 pm, about 60 pm to about 120 pm, about 70 pm to about 100 pm, about 75 pm to about 95 pm, or about 80 pm. at approximately 90 pm, and ranges between any two of these values or less than any of these values. In some embodiments, the separator has a dry thickness of about 60 pm to about 120 pm. In other embodiments, the separator has a dry thickness of about 75 pm to about 95 pm.

In one aspect, there is provided a separator and/or an electrochemical cell comprising said separator, which includes a non-conductive porous material having a maximum pore size of about 19 pm. In one aspect, there is provided a separator and/or an electrochemical cell comprising said separator, which includes a non-conductive porous material having an average pore size of about 1 micron to about 6 pm. In another aspect, there is provided a separator and/or an electrochemical cell comprising said separator, which includes a non-conductive porous material having an air permeability of about 0.5 cm3/cm2.s to about 3.8 cm3/cm2.s at 125Pa. In yet another aspect, there is provided a separator and/or an electrochemical cell comprising said separator, which includes a non-conductive porous material having an air permeability of approximately 8.33 cm3/[cm2.s] (500 cc/cm2/min ) at approximately 50 cm3/[cm2.s] (3000 cc/cm2/min), at 1KPa. In another aspect, there is provided a separator and/or an electrochemical cell comprising said separator, which includes a non-conductive porous material having a basis weight of about 20 g/m2 to about 32 g/m2. In yet another aspect, there is provided a separator and/or an electrochemical cell comprising said separator, which includes a non-conductive porous material having a dry thickness of about 60 pm to about 120 pm. Each of these aspects is combinable with the other aspects and realizations.

In various embodiments, the separator described herein is referred to as "Paper 1." Generally, the number of turns of the separator material used in the electrochemical cell can be optimized for a given application and/or to achieve a desired performance within the cell. The separator disclosed herein allows the use of less than 3 turns of paper. In some embodiments, the Paper separator 1 may be designed to include a single layer of the non-conductive porous material sheet rolled twice. In various embodiments, the separator includes more than about 1 and less than about 4, more than about 1.1 and less than about 3, more than about 1.2 and less than about 2, or more than about 1.3 and less than about 1.8 (in the (a shell number greater than 1 indicates that some degree of separator overlap is present within the cell). In some embodiments, the separator includes less than about 2 envelopes of the non-conductive porous material. In some embodiments, the separator includes less than about 3 shells of the non-conductive porous material. In other embodiments, the number of turns is greater than about 3 and less than about 4. It should be noted that the number of "wraps" for a wound separator configuration indicates the number of windings of the separator, which may itself be multilayer or single layer. For example, a 1x2 wrapper indicates that the separator has 2 wrappers of a single layer separator. In some embodiments, the separator may be designed to include a single layer of the non-conductive porous material sheet rolled twice.

The separator described herein has several advantages with respect to pore size to avoid short circuits resulting from the transport of active materials, improved mechanical strength and electrolyte permeability, low electrical resistance, sufficient flexibility, high chemical resistance and high thermal stability. Without adhering to any particular theory, it is generally believed that the separator disclosed herein is advantageous because it occupies or consumes less volume, compared to a conventional separator, which decreases the total dry thickness of the separator and leaves room for an additional amount of active ingredients, such as those of anodic or cathodic electrodes.

Additionally, the separator acts to improve short circuit resistance, since a barrier with a small pore size provides internal short circuit resistance that would not be possible with conventional separators that do not have the features described herein.

The performance of the electrochemical cell including the separator of the present technology can be further improved with the use of improved zinc anode material, compared to that of cells manufactured with conventional zinc anode material. Therefore, in various embodiments, the separator of the present technology is used in conjunction with the anode that includes high fines content (HF) anode active materials, where the fines content is higher and the coarse content is less than the of conventional standard zinc powders. In various embodiments, the anode active material may have a particle size distribution of less than about 15% by weight powder, about 10% by weight to about 70% by weight fine particles, and about 5% by weight to about 35% by weight of coarse particles. In some embodiments, the anode active material of the present technology has a particle size distribution of less than about 10% by weight of powder, about 15% by weight to about 65% by weight of fine particles and about 5% in weight to approximately 25% by weight of coarse particles. A suitable zinc particle size distribution may be one in which about 25% to about 45% by weight of the anode active material, with respect to the total amount of anode active material, has a particle size of less than about 75 pm, about 5% to about 25% by weight with respect to the total zinc alloy has a particle size greater than about 150 microns, about less than 2% by weight of the total zinc alloy has a particle size greater than 425 pm, and less than 10% by weight of the anode active material, with respect to the total amount of anode active material, has a particle size less than about 45 pm.

In some embodiments, the type of anode active material used, having an optimized particle size distribution and bulk density, may be similar to that described in substantial detail in United States Patent Publication Number 2015/0037627. In other embodiments, the anode active material has a bulk density of about 2.00 g/cm3 to about 4.15 g/cm3, in some embodiments of about 2.25 g/cm3 to about 3.85 g/cm3, in some embodiments of about 2.50 g/cm3 cm3 to about 3.50 g/cm3, in some embodiments from about 2.60 g/cm3 to about 3.35 g/cm3 and in some embodiments from about 2.70 g/cm3 to about 3.15 g/cm3.

Although the embodiments described herein generally relate to alkaline cells, they are applicable to other suitable electrochemical cells including, for example, alkaline cylindrical cells, e.g., metal-metal oxide cells, as well as galvanic cells, such as metal-air cell, for example, zinc-air cell. Among the cylindrical metal-metal oxide cells and metal-air cells, the anode material is applicable to those shaped for AA, AAA, AAAA, C or D cells. These include, for example, LR03 alkaline cells , LR6, LR8D425, LR14, LR20. Electrochemical cells have applications in non-cylindrical cells, such as planar cells (e.g., prismatic cells and button cells) and rounded planar cells (e.g., having a racetrack-shaped cross section). Metal-air cells including the anode described herein can be usefully constructed as button cells for various applications, such as batteries for hearing aids and in watches, stopwatches, calculators, laser pointers, toys and other novelties. Suitable electrochemical cells may also include any metallic air cell that uses flat, curved or cylindrical electrodes. The use of the anode as a component in other forms of electrochemical cells is also contemplated.

The anode of the electrochemical cell is a gelled anode that includes an anode active material, an electrolyte (optionally alkaline), optionally a gelling agent and optionally one or more surfactants as corrosion inhibitors. The gelled anode may also include other components or additives such as, for example, absorbents, inorganic gas formation inhibitors and additives to control the electrical short circuit between the anode and cathode electrodes. The anode active material may include a zinc alloy that includes from about 20 ppm to about 750 ppm of one or more alloying elements selected from bismuth, indium, lead and aluminum. In some embodiments, the zinc alloy includes bismuth and indium as major alloying elements, each at a concentration of about 150 ppm, 200 ppm, or 250 ppm. The anode includes high fines content (HF) anode active materials, as described earlier herein, where the fines content is higher and the coarse content is lower than that of conventional standard zinc powders.

The gelled anode may include an alkaline electrolyte and, in some embodiments, an alkaline electrolyte having a relatively low hydroxide content. Suitable alkaline electrolytes include, for example, aqueous solutions of potassium hydroxide, sodium hydroxide, lithium hydroxide, as well as combinations of two or more thereof. However, in a particular embodiment an electrolyte containing potassium hydroxide is used. In other embodiments, the alkaline electrolyte includes water and potassium hydroxide.

Advantageously, the electrolytes have a lower concentration of hydroxide ions in the electrolyte than those used in conventional cells. For example, the electrolyte may have a hydroxide concentration (e.g., potassium hydroxide) of less than about 36%, based on the total weight of the electrolyte. This includes a hydroxide concentration of less than about 35%, less than about 34%, less than about 32%, less than about 30%, less than about 29%, or less than about 28% based on the total weight of the electrolyte. In various embodiments, the electrolyte has a hydroxide concentration of about 25% to about 34%, about 26% to about 34%, about 27% to about 34%, or about 28% to about 32%, and ranges between any two of these values or less than any of these values. This includes a hydroxide concentration of about 35%, about 34%, about 32%, about 31%, about 30.5%, about 30%, about 29%, or about 28% based on the total weight of the electrolyte. In an illustrative embodiment, the hydroxide concentration of the electrolyte is about 27% to about 31% by weight, based on the total weight of the electrolyte.

The anode can be prepared by formulating an electrolyte, preparing a coated metal anode, including the gelling agent, and then combining the electrolyte and the coated metal anode to form a gelled anode. The gelling agent of the present disclosure may include, for example, a highly cross-linked polymeric chemical compound having negatively charged acidic groups, such as a polyacrylic acid gelling agent having a high degree of cross-linking.). Highly cross-linked polyacrylic acid gelling agents are commercially available under the names Carbopol® (Carbopol® 940, Carbopol® 934 or Carbopol® 674) from Lubrizol Corporation (Wickliffe, Ohio), Flogel® (e.g., Flogel® 700 or Flogel® 800) from SNF Holding Company (Riceboro, GA) and Polygel® (e.g., Polygel® CK or Polygel® CA) from 3V Sigma S.P.A. (Georgetown, SC), among others, are suitable for use in accordance with this disclosure. The concentration of the gelling agent in the gelled anode may be from about 0.20 wt.% to about 1.5 wt.%, about 0.40 wt.% to about 1.00 wt.%, about 0.60 wt. 0.625% by weight to approximately 0.675% by weight, with respect to the total weight of the gelled anode.

The electrochemical cell cathode may include any active cathode material generally recognized in the art for use in alkaline electrochemical cells. The active cathode material can be amorphous or crystalline, or a mixture of amorphous and crystalline. For example, the cathode active material may include, or be selected from, a copper oxide, a manganese oxide of electrolytic, chemical or natural type (for example, EMD, CMD, NMD or a mixture of two or more thereof ), a silver oxide and/or a nickel oxide or hydroxide, as well as a mixture of two or more of these oxides or hydroxides. Suitable examples of positive electrode materials include, but are not limited to, MnO<2>(EMD, CMD, NMD and mixtures thereof), NiO, NiOOH, Cu(OH)<2>, cobalt oxide, PbO<2>, AgO , Ag<2>O, Ag<2>Cu<2>O<3>, CuAgO<2>, CuMnO<2>, Cu Mn<2>O<4>, Cu<2>MnO<4>, Cu <3>-xMnxO<3>, Cu-i_xMnxO<2>, Cu<2>-xMnxO<2>(where x<2), Cu<3>-xMnxO<4>(where x<3), Cu< 2>Ag<2>O<4>, or a combination of two or more thereof.

An exemplary embodiment of an alkaline electrochemical cell is described in PCT publication number WO 2016/183373.

As detailed elsewhere herein, the electrochemical cells of the present disclosure have been found to exhibit improved performance characteristics, which can be measured or tested in accordance with various methods according to the American National Standards Institute (ANSI). The results of various tests of cells of the present disclosure are detailed below in the examples.

The following examples describe various embodiments of the present disclosure. Other embodiments within the scope of the appended claims will be apparent to one skilled in the art considering the specification or practice of the disclosure provided herein.

Examples

In the examples presented below, electrochemical cells including the separators of the present technology were tested for DSC performance, partial discharge cell gasification, non-discharge cell gasification, and conditions after storage.

General. Characterization. The air permeability of the separators was determined using a PMI capillary flow porometer and is expressed in cm3/[cm2.s] (cc/cm2/s or cc/cm2/min). The basis weight of the separators was determined according to ISO 536 (2012), which is expressed in g/m2. The dry thickness of the separators was determined with a Mitutoyo Absolute Gauge using a 10 mm diameter flat probe with low contact force. measurement, and is expressed in pm. Pore size was determined using the PMI capillary flow porometer and is expressed in pm.

Example 1. Preparation of LR6 cells. Control cells were prepared that had a conventional 1x3 separator. The conventional separator has a mean pore size of 9 pm, a maximum pore size of 32 pm measured with a PMI capillary flow porometer, an air permeability of 22.1 cm3/cm2 s at 125 Pa, a basis weight of 23 g/ m2 and a dry thickness of 80 pm.

The cells were also prepared using a 1x2 wrapper of a nonwoven paper (Paper 1) that had a pore medium size of 1-6 pm measured with a PMI capillary flow porometer, an air permeability of 1-4 cm3/ cm2.s at 125 Pa, a desired basis weight of 20-32 g/m2 and a dry thickness of 60-120 pm.

Example 2. Electrochemical cells can be tested according to American National Standards Institute (ANSI) methods. For example, the ANSI data represented in the figures are from tests performed in accordance with ANSI C18.1M, Part 2-2011. These tests include determining cell performance/longevity under various discharge modes, including pulsed cell discharge, intermittent cell discharge, high temperature (HT) storage performance, or digital still camera ( DSC), among other tests. Testing also includes determining the performance/longevity of the cells by discharging them into various devices such as portable lighting, CD games, digital audio and remote clock radios, toys, and heavy industrial flashlights (HIFT). The results of various cell tests of the present disclosure are detailed below.

Figure 1 shows the ANSI average discharge performance of LR6 alkaline cells made with conventional zinc anode (no higher level of fines) and conventional separator with a 68% zinc loading. It was observed that the average ANSI of seven tests for the Paper 1 separator of the present technology improves approximately 2.3% compared to the conventional separator. The test that improved the most was in self-care (750 mA, 2 minutes (min)/hour (h), 8 h/day), which improved approximately 18.2%, as seen in Figure 2. Additionally, the test of the toy (3.9 ohms (O), 1 hour/day) improved by 0.7%. No statistical impact on performance was observed among the other tests, including DSC (digital still camera, 1500 mW 2 seconds (s), 650 mW 28 s 5, min/h), handheld lighting (3.9 n, 4 min/h , 8 hr/day), CD games (250 mA, 1 hr/day), digital audio testing (100 mA, 1 hr/day), and remote clock radio (50 mA, 1 hr/12 hr, 24 hr ).

Performance gains with a 1x2 Paper 1 separator were confirmed after storing the cells at high temperature (HT). Figure 3 shows the average LR6 HT performance of the toy test after 1 week of storage at 71°C (160°F), (1 HT), and of the play and DSC tests, both after 2 weeks of storage. storage at 54.4°C (130°F) (1/2 HT). In Figure 3 it is seen that cells made with 1x2 Paper 1 exhibit a net gain of 7% over conventional cells made with standard 1x3 separator paper. The main gain after HT storage occurred in the DSC test, which amounted to 17%, as shown in Figure 4. The gains in discharge performance with the 1x2 separator arrangement can be maximized by increasing the zinc loading above 68%.

Figure 5 shows the average ANSI non-delay performance of LR6 cells made with 11x2 Paper with pre-wetted (PW) KOH solution levels of 1.45 grams (g), 1.50 g and 1.55 g, compared to data from reference cells made with conventional 1x3 separator paper. The cells used zinc HF with a zinc loading of 70%. The average ANSI of cells made with HF zinc and 11 x2 Paper wrapper improved by 2% to 4% relative to the cell made with HF zinc and a conventional 1x3 wrapper separator.

DSC performance after one month of storage (lRT) improved from 3% to 8% and in personal care improved from 11% to 15%, relative to the cell made with zinc HF and the conventional paper wrapper separator lx3, depending on the amount of prewetted electrolyte, as shown in Figure 6 and Figure 7, respectively. The corresponding HT performance for LR6 cells made with 70% HF zinc is illustrated in Figure 8. The average gains ranging from 2.1% to 8.6% correspond to the DSC and toy tests after 1HT storage and the game and DSC after 1/2 HT storage.

While certain embodiments have been illustrated and described, it should be understood that changes and modifications may be made thereto in accordance with common knowledge in the art without departing from the following claims.

The embodiments, illustratively described herein, may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms "comprising", "including", "containing", etc., will be read broadly and without limitation.

As will also be understood by one skilled in the art, all language such as "up to", "greater than", "less than" and the like includes the cited number.

Claims (11)

1. An alkaline electrochemical cell comprising: a cathode; a gelled anode comprising an anode active material and an electrolyte, wherein the active anode material comprises a zinc alloy; and a separator arranged between the cathode and the anode; wherein the separator comprises a non-conductive, non-woven porous material comprising polyvinyl alcohol and having the following properties, determined using a PMI capillary flow porometer: an average pore size of about 1 pm to about 5 pm, a maximum pore size of about 19 pm and an air permeability of about 0.5 cm3/[cm2 s] to about 3.8 cm3/[cm2 s] at 125 Pa, where as used herein, "about" means /-10%. 2. The alkaline electrochemical cell of claim 1, wherein the separator comprises less than 3 complete envelopes of the non-conductive porous material. 3. The alkaline electrochemical cell of claim 1, wherein about 20% to about 45% by weight of the anode active material with respect to the total amount of anode active material has a particle size of less than about 75 pm, about 8% to about 25% by weight with respect to the total zinc alloy has a particle size greater than about 150 pm, and less than 10% by weight of the anode active material with respect to the amount total anode active material has a particle size less than about 45 pm, where, as used herein, "about" means /-10%. 4. The alkaline electrochemical cell of claim 1, wherein the anode active material has an apparent density of about 2.50 g/cm3 to about 3.30 g/cm3, wherein, as used herein, "about " means /-10%. 5. The alkaline electrochemical cell of claim 1, wherein the electrolyte has a hydroxide concentration of about 24% by weight to about 37% by weight, wherein, as used herein, "about" means /-10%. 6. The alkaline electrochemical cell of any preceding claim, wherein the zinc alloy comprises about 130 ppm to about 270 ppm of bismuth and about 130 ppm to about 270 ppm of indium, wherein, as used in the In this document, "approximately" means /-10%. 7. An alkaline electrochemical cell separator comprising a non-conductive porous material, wherein the separator has an average pore size of about 1 pm to about 5 pm, a maximum pore size of about 19 pm, and an air permeability of about 0.5 cm3/[cm2.s] to about 3.8 cm3/[cm2.s] at 125 Pa, determined using a PMI capillary flow porometer, where as used herein, "approximately" means /-10 %. 8. The alkaline electrochemical cell of claim 1 or the alkaline electrochemical cell separator of claim 7, wherein the separator has an air permeability of approximately 8 cm3/[cm2.s] (500 cc/cm2/min) at approximately 50 cm3/[cm2.s] (3000 cc/cm2/min), at 1 KPa, where, as used herein, "approximately" means /-10%. 9. The alkaline electrochemical cell of claim 1 or the alkaline electrochemical cell separator of claim 7, wherein the separator has a basis weight of about 20 g/m2 to about 32 g/m2, wherein as used In this document, "approximately" means /-10%. 10. The alkaline electrochemical cell of claim 1 or the alkaline electrochemical cell separator of claim 7, wherein the separator has a dry thickness of about 60 pm to about 120 pm, wherein as used herein , "approximately" means /-10%. 11. The alkaline electrochemical cell separator of claim 7, wherein the separator is permeable to hydroxide ions and water.